Registration control timing switch for web-processing machine

ABSTRACT

Web-cutting apparatus wherein an individual cutting zone on a web must be properly positioned (i.e., in register) relative to a cutting blade at a predetermined time to insure a proper cut requires control means, including a timing or selector switch, for determining if registry exists and for making appropriate changes in web speed if it does not. The timing or selector switch comprises a rotatable shaft synchronized with operation of the cutting blade. A pair of ferrous metal discs are mounted on and rotatable with the shaft. Each disc has a notch in its periphery, and a pair of magnetic pickup devices, one for each disc, are mounted in fixed positions relative to their respective discs. Each pickup device provides an electrical pulse upon passage of the notch in its associated disc as the latter rotates. The interval between the pulses produced by the two pickups for each rotation of the shaft serves as the desired time interval. The duration of the time interval can be varied by changing the angular distance between the pickup devices by moving either one or both to a different position. The time interval itself can be shifted by changing the positions of both pickup devices without changing the angular distance between them to effect advancement or retardation of the web to achieve registry.

United States Patent Bodendoerfer June 19, 1973 REGISTRATION CONTROLTIMING SWITCH FOR WEB-PROCESSING MACHINE [75] Inventor: Raymond E.Bodendoerfer,

Brookfield, Wis.

[73] Assignee: Paper Machinery Corporation,

Milwaukee, Wis.

[22] Filed: Dec. 29, 1971 [21] Appl. No.: 213,502

52 us. C1. 226/30, 83/74 7/1963 Huck 226/30 X Primary Examiner-RichardA. Schacher Assistant Examiner-Gene A. Church Attorney-James E. Nilles[57] ABSTRACT Web-cutting apparatus wherein an individual cutting zoneon a web must be properly positioned (i.e., in register) relative to acutting blade at a predetermined time to insure a proper cut requirescontrol means, including a timing or selector switch, for determining ifregistry exists and for making appropriate changes in web speed if itdoes not. The timing or selector switch comprises a rotatable shaftsynchronized with opera tion of the cutting blade. A pair of ferrousmetal discs are mounted on and rotatable with the shaft. Each disc has anotch in its periphery, and a pair-of magnetic pickup devices, one foreach disc, are mounted in fixed positions relative to their respectivediscs. Each pickup device provides an electrical pulse upon passage ofthe notch in its associated disc as the latter rotates. The intervalbetween the pulses produced by the two pickups for each rotation of theshaft serves as the desired time interval. The duration of the timeinterval can be varied by changing the angular distance between thepickup devices by moving either one or both to a different position. Thetime interval itself can be shifted by changing the positions of bothpickup devices without changing the angular distance between them toeffect advancement or retardation of the web to achieve registry.

7 Claims, 10 Drawing Figures PATIENIED 3.739.968

sum 1 or 4 ADVANCE ZONE -2l RETARD ZONE FIG. 3

PAINTED- 9973 same er 1:

REGISTRATION CONTROL TIMING SWITCH FOR WEB-PROCESSING MACHINE BACKGROUNDOF THE INVENTION 1. Field of the Invention This invention relatesgenerally to registration control systems for web-processing apparatus,such as cutting machines which cut blanks from a web of materialcontaining repeated printed designs. More particularly, it relates totiming or selector switch means used in such control systems to achieveregistry.

2. Description of the Prior Art Typical apparatus for cutting blanksfrom a web of material containing repeat printed designs andcorresponding register marks comprises a reciprocating cutting blade,intermittently-active feed rolls synchronized with the blade cycle forfeeding a predetermined length of web to the blade, andcontinuously-active constant speed metering rolls which control webspeed and, thus, the amount of web fed to the feed rolls. The meteringrolls are driven through a variable speed transmission device whichincorporates a correction motor which is selectively energizeable by acorrection signal for rotation in either direction for short periods oftime to make minor momentary adjustments in web speed, i.e., web lengthfed to the feed rolls. Such speed adjustments are necessary to avoidmisregistration of the designs with the cutting blade due to undesirableand unpredictable minute differences in spacing between designs whicharise during printing of the design on the web.

Detection and correction of potential misregistration is accomplished bya control system which detects the position of a particular registermark with respect to the blade at a given point in time in the operatingcycle of the blade. If it appears that the register mark is in registry,no correction signal is sent by the control system to the correctionmotor. However, ,if misregistration is indicated and correction isrequired, the control system provides an appropriate control signal(advance or retard) to the correction motor to momentarily changeweb-feed speed. Some control systems include a photoelectric scannerlocated in a predetermined distance ahead of the blade for sensing thepassage of register marks printed on the edge of the web (one mark beingprovided for each design) and for providing a register mark pulse uponpassage of each mark. Such control systems further include a timing orselector switch responsive to blade position for defining a scanningarea, for each cycle of blade operation. The scanning area is dividedinto an advance zone, an inregister zone, and a retard zone. Suchcontrol systems also include circuitry for determining where eachregister mark pulse from the scanner occurs in the scanning area andprovides an appropriate correction signal to the correction motor.

In practice, it sometimes happens that the designs printed'on the webextend into the region seen" by the scanner, i.e., the scanning area,and this would ordinarily result in false pulses being produced by thescanner. To compensate for this, it is necessary to be able to narrowthe so-called scanning area seen by the scanner. It is also necessary tobe able to shift the scanning area by manual controls so as to achieveprope registration.

Some prior art timing switches are capable of providing either or bothof these functions. One such type of prior art timing switch employs arotating electrically conductive disc with a non-conductive insert inthe periphery and commutating brushes which ride on the periphery of thedisc. In such switches, the size of the insert determines the size ofthe scanning area and the in register interval and changing the positionof the brushes shifts the scanning area. However, to make desirableadjustments in some installations, the cutting machine and switch mustbe stopped and the discs must be replaced or the brushes repositioned.While such prior art timing or selector switches are generallysatisfactory for their intended purpose, it is impossible to makeadjustments by means embodied in the switch itself. Furthermore,switches using the commutation principle are subject to mechanical wearwhich can affect their electrical operation and necessitates replacementof worn parts.

SUMMARY OF THE INVENTION Web-processing apparatus and control meanstherefor in accordance with the present invention contemplates a webcontaining repeated designs and corresponding register marks along theside edge of the web (normally one mark for each design). Minute errorsin spacing occur between each design due to printing techniquesemployed. Furthermore, portions of each design lie in the same path onthe web as the register marks and tend to give false indications to thesensing device unless appropriate measures are taken.

The web-processing apparatus comprises a processing device, such as acutter, for performing a process or operation on each design; a feedmeans, such as intermittently operable feed rollers, for repeatedlyfeeding a predetermined length of web to the cutter; and a meteringmeans, such as constant speed metering rollers, for controlling the rateof speed at which the web is supplied to the feed, i.e., the amount ofweb supplied to the feed rollers.

The control means for maintaining the designs in registry with theprocessing device or cutter comprise correction means, such as adifferential gear box through which the metering rollers are driven anda selectively energizable correction motor (operable momentarily inforward or reverse) on the transmission, for momentarily changing webspeed. The control means also comprise scanning means, such as aphotoelectric sensing device, a predetermined distance ahead of thecutter for sensing passage of each registry mark and for providing aregister mark pulse in response thereto. The control means furthercomprise a selector or tim ing switch, hereinafter more fully described,responsive to the operative position of the cutter during each cycle ofcutter operation for providing output signals which define a scanningarea (actually a time interval) within which or during which theregister mark pulse must occur in order for a proper cutting operationto ensue or for appropriate advance or retard adjustments to be made toweb speed. The control means finally comprise a control circuit forcomparing the relationship of the register mark pulse from the scannerwith the scanning interval from the selector switch and for providing acorrection signal (advance or retard) to the correction motor in theevent the register mark pulse occurs at a time other than during aso-called dead area or in register zone in the scanning interval.

In accordance with the present invention, the selector or timing switchis designed so that the scanning interval can be adjusted in two ways.First, the size (measured in the direction of web travel) of thescanning interval can be adjusted so as to prevent false signals fromthe scanner (caused by the scanner seeing portions of designs as well asregister marks) from effecting a change in web speed. Second, theposition of the scanning interval can be shifted to advance or retardweb speed so that cutting occurs in the proper place on the web. Theselector or timing switch comprises a support frame and rotatable driveshaft mounted on the frame and rotatable at least one revolution foreach cycle of cutter operation, although other ratios are possible. Twocircular discs of magnetizable metal are mounted on the shaft and arerotatable therewith. Each disc is provided with a notchor cutout in theperiphery which provides a magnetic discontinuity in the disc. The discsare preferably disposed so that the notches are spaced 180 apart. A pairof magnetic pickup devices, one for each disc, is mounted on adjustableyokes on the frame. The magnetic pickups are spaced apart from eachother by a predetermined angular distance and have a predeterminedlocation with respect to the frame. Each complete revolution of theshaft and discs causes the magnetic pickups to produce a pair ofspaced-apart electrical pulses and the interval between the pulsescorresponds to the scaning interval. Means are provided to shift themagnetic pickup yokes either to change the length of the interval or toshift it so as to advance or retard web speed.

Controls for web-processing apparatus in accordance with the inventionemploy an improved timing or selector switch which defines a so-calledscanning area which can be selectively adjusted in several ways whilethe web-processing apparatus and switch are in operation. In particular,the length of the scanning area or the position of the scanning area orboth can be adjusted. Furthermore, no contact or friction occurs betweenswitch components which produce electrical pulses and, consequently, nowear occurs and no replacement parts are needed. Adjustment or changesof output signals from the selector switch can be accomplished withoutthe necessity of substituting components of different size orconfiguration and the switch is ideally suited for high-speed operation.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram ofweb-cutting apparatus incorporating cut-off register control means inaccordance with the present invention;

FIG. 2 is a cross-section view of the web-cutting apparatus shownschematically in FIG. 1;

FIG. 3 is an enlarged top plan view of a portion of the web shown inFIGS. 1 and 2;

FIG. 4 is an enlarged front elevation view of a selector switch shown inFIG. 1;

FIG. 5 is a front view, partly in phantom, of the selector switch shownin FIG. 4;

FIG. 6 is a cross-section view of the selector switch taken along lineVI--Vl of FIG. 5;

FIG. 7 is a top plan view of the selector switch shown in FIGS. 4, 5 and6;

FIG. 8 is a cross-section view of locking devices on the selector switchtaken along line VIII--VIII of FIG.

FIG. 9 is a cross-section view of a portion of the cutter adjustmentmeans on the selector switch taken along line IXIX of FIG. 4; and

FIG. 10 is a circuit diagram of portions of the control means shown inFIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1 of thedrawings, there is shown schematically a web-cutting machine and controlcircuitry therefor in accordance with the present invention. The cuttingmachine operates to cut blanks from a web 10 of material, such as paper,on which evenly spaced, repeat designs 112 are printed, as shown in FIG.3. Web 10 is provided in a path along one edge thereof with evenlyspaced printed register marks 14, one mark being provided for eachdesign. However, minute errors occur in spacing between successivedesigns and successive register marks caused during printing. Typically,each register mark 14 has a width (measured in the direction of webtravel) of about 3/32 inch to inch. Furthermore, in some instances, thedesigns extend into the path occupied by the register marks and thisresults in erroneous cutting.

WEB CUTTING MACHINE As FIGS. 1 and 2 show, the cutting machine comprisesa suitable supporting framework or structure 16 on which a web supplyroller 18, decurling rollers 20, web guides 22, and web-support plates24 are mounted and through or around which web 10 passes. The cuttingmachine also comprises metering means, such as a metering roll 26 and anassociated nip-roller 28 which normally feeds web 10 at a predeterminedconstant rate of speed to web feeding means, such as a pair ofintermittently operable feed rollers 30 and 32. The feed rollers 30 and32, which are adjustable, periodically feed a predetermined length ofweb to intermittently operable cutting means such as the cutting bladesor dies 34 and 36.

As FIG. 2 shows, operating power for the cutting machine is provided bya main drive electric motor 38 which rotates a main drive shaft 40through a drive means 42. Main drive shaft 40 is connected through adrive means 44 to drive an eccentric cam 46 to which a reciprocallymovable cutter blade drive rod 48 is connected. Drive rod 48 effectsreciprocating cutting movement of movable blade or die 34 at a constantrate of speed. Main drive shaft 40 is also connected through anotherdrive means 50 to drive a secondary drive shaft 52 which is mounted forrotation on framework 16. Secondary drive shaft 52 is connected througha gear train 54 to drive the feed rollers 30 and 32 which rotateintermittently. It is to be understood that the movable cutting blade ordie 34 operates in synchronism with the feed rollers 30 and 32, i.e.,each advance of a blank by the feed rollers is followed by acorresponding cutting operation. Furthermore, it is to be understoodthat the gears in gear train 54 are so-called change gears which arereplaceable by gears of various sizes depending on the size of theblanks to be cut from the web.

Secondary drive shaft 52 is also connected through another drive means56 to the input gear 58 of a differential transmission 60 which has anoutput gear 62 for driving metering roll 26.

Differential transmission 60 is provided with a correction motor 64momentarily energizable in forward or reverse directions to increase ordecrease, respectively, the speed of output gear 62 and thus change thespeed of metering roll 26 and the amount of web fed thereby to feedrollers 30 and 32.

A timing or selector switch 68, hereinafter described in detail, ismounted on framework 16 and a rotatable drive shaft 70 thereof isprovided with a drive gear 72 which meshes with a gear 74 on a shaft 76of feed roll ers 32.

A scanner 80 is mounted on framework 16 a predetermined distance aheadof the cutting blades 34 and 36. Scanner 80, preferably of the diffusedreflection of light type, comprises a light source 82, a lens 84 whichfocuses the light at a point 86 in the path of the register marks on theweb, as FIGS. 1 and 4 show, and a pair of photoelectric cells 88 and 90which are also focused on point 86. Scanner 80 is responsive only to theleading edge of each register mark and produces a single sharpelectrical pulse for each register mark which is suitably amplified andutilized as hereinafter described. If preferred, however, other types ofscanners could be employed.

CONTROL SYSTEM GENERALLY Referring to FIG. 1, it is seen that a controlsystem (shown schematically in FIG. 1 and in detail in FIG. comprisesscanner 80, timing or selector switch 68, correction motor 66 ontransmission 60, a comparator circuit 92, comprising a thyratron circuit94 and a timedelay circuit 96 for comparing output signals from scanner80 and selector switch 68 to determine if correction motor 66 is to beenergized, a motor-reversing circuit 98 operable in response to controlcircuit 92 to effect operation of correction motor 66, and a source ofpower 100 and a power supply circuit 102 for providing operating powerto the several elements in the control system, as hereinafter describedin connection with FIG. 110.

TIMING SWITCH Timing or selector switch 68 shown in FIGS. 4 through 9 ofthe drawings comprises a supporting structure having a back plate 104, afront plate 106, and four studs 108 for securing the plates together inspaced-apart relationship. Back plate 104 is provided with suitableflanges 110 for rigidly securing switch 69 to the supporting framework16 of the cutting machine. Back plate 104 carries a bearing 112, shownin FIG. 6, for supporting one end of rotatable switch shaft 70 which isadapted to be driven, as hereinbefore explained, through suitable gears72 and 74 by feed roll 32. The other end of switch shaft 70 is supportedon a bearing 1114i hereinafter described.

First and second adjacent circular discs 116 and l 18, made offerromagnetic material such as steel, are mounted on switch shaft 70 forrotation therewith. Each disc is provided with set screw means 120 onits hub to permit mounting and angular adjustment of the disc withrespect to switch shaft 70. The discs 116 and 118 are provided withnotches or cutouts 122 and 124, respectively, on their peripheries foractuating magnetic pickup devices 126 and 128, respectively, located inproximity to the discs.

Each magnetic pickup device 126 and 128 is understood, for example, tocomprise a small magnet and a coil solidly encapsulated within a ruggedstainless steel shell. Each magnetic pickup generates a voltage outputor electrical pulse when ferro-magnetic material enters the magneticfield surrounding a pole piece at the sensing end of the pickup withsufficient speed. More specifically, the dynamic discontinuity providedby the notch or cutout in each disc as it enters the magnetic fieldaround its associated magnetic pickup device produces an electricvoltage or pulse. Such magnetic pickups are known in the art and thepresent invention em ploys a type designated Model 4947 manufactured byAutomation Engineering Co., Inc, Mequon, Wisconsin, and shown in thatcompanys bulletin MPB-269. The pulses from the magnetic pickup devices126 and 128 are used to actuate relays 2'7 2 and 274, hereinafterdescribed. Each relay 272 and 274 has a delayed break, i.e., itscontacts are adjustable to close and stay closed for a predeterminedinterval of time, on the order of 0.05 to 1 seconds, depending on thetime interval selected. Such a relay is known and is described inbulletin MP-969 of Electro Products Laboratories, Inc, Chicago,Illinois.

Magnetic pickup device 128 is supported in proximity to disc 118 bymeans of an adjustable yoke 134 which comprises an arm 136 which isrigidly secured to the inner end of a cylindrical sleeve 1138surrounding but unattached to switch shaft 70. The outer end of sleeve138 extends through front plate 166 of the switch and has a combinedadjustment knob 114W) and dial plate 142 rigidly secured to the sleeve.Knob 1140 is supported by bearing 1 14 on the outer end of switch shaftwhich allows for relative movement between the knob and the switchshaft.

Magnetic pickup device 126 is supported in proximity to disc 116 bymeans of an adjustable yoke 144 which comprises an arm 146 which isrigidly secured to the inner end of a cylindrical sleeve 148 surroundingbut unattached to sleeve 138 of yoke 134 hereinbefore described. Theouter end of sleeve 148 extends through front plate 106 of the switchand has a combined adjustment knob and dial plate 150 rigidly securedthereto. Dial plate 142 is recessed within dial plate 150 but isrelatively movable with respect thereto. More specifically, lockingdevice 152 comprises a head 156, a collar I57, and a threaded shank 158which engages a threaded opening 160 in dial plate I56. When lockingdevice 152 is tightened, collar 157 bears against both dial plates i142and 150 and prevents relative movement between the dial plates and theirassociated yokes 134 and 144, respectively. Locking device I54 comprisesa head 162, a collar 164 and a threaded shank 166 which engages athreaded opening in front plate 106. When locking device 156 istightened, collar I64 bears against dial plate 150 and relative movementbetween dial plate 150 and front plate W6 is prevented.

'As FIGS. 41, 6, 7 and 9 show, a cutting adjustment I gear 170 isrigidly secured to sleeve 148 of outer yoke 148 by a set screw I72 andis rotatable by means of a cutting adjustment knob 174i and gear 1176 onfront plate 106 of the switch to effect simultaneous rotational movementof both yokes 134 and M41 (when they are locked together by lockingdevice 152) to make timing adjustments in the registration of web It)with cutting blades 34 and 36. Referring to FIG. 5, counterclockwiserotation of both cutting yokes I34 and 144 by means of adjusting knob174 effects an advance" registration adjustment and clockwise rotationeffects a retard adjustment.

CONTROL SYSTEM IN DETAIL FIG. 10 is a circuit diagram of the controlsystem in accordance with the invention. Generally considered, thecontrol system comprises a power source 100, a power-supply circuit 102,a scanner and pulse amplifier circuit 180 including scanner 80, aselector switch circuit 182 including selector switch 68, a comparatorcircuit 92 including thyratron circuit 94 and time-delay circuit 96, andmotor-reversing circuit 98 including correction motor 66.

Power source 100 supplies electrical power such as 110 volt, 60 cyclealternating current to two supply lines 184 and 186. Power supplycircuit 102 comprises a power transformer 1 having a primary winding188a and three secondary windings 188b, 188c and 188d. An on-off switch190 is in circuit between power line 184 and primary winding 188a oftransformer 188. Power supply circuit 102 further comprises a full-waverectifier tube 192 to which the secondary windings 188b, 188C and 188dare connected, thereby providing a regulated DC voltage to controlsystem components and circuits, as hereinafter appears.

Scanner and pulse-amplifier circuit 180 comprises light source 82,photoelectric cells 88 and 90 which are connected in parallel, and anamplifier tube 194 which amplifies a pulse received from thephotoelectric tubes when the light beam from light source 82 isinterrupted by register mark 14 on web 10. Heater 1940 of tube 194 isconnected across secondary winding 188d of power transformer 188.Cathode 194b of tube 194 is connected to ground and plate 194c isconnected to power supply circuit 102. Biasing grids 194d and 194e areconnected to the cathode and plate, respectively, in tube 194. Controlgrid 194f of tube 194 is connected through a capacitor 196 to thecathodes 198 of photoelectric cells 88 and 90. The amplified registermark pulse is transmitted through a conductor 200 to comparator circuit92, as hereinafter described.

Comparator circuit 92 includes thyratron circuit 94 and time-delaycircuit 96. Thyratron circuit 94 comprises two thyratron tubes 202 and204 which are understood to be grounded and ungrounded alternately byselector switch circuit 182, as hereinafter described. Thyratron tube202 commprises a heater element 202a which is connected across secondarywinding 188d of power transformer 188. The cathode 202b of tube 202 isconnected to power supply circuit 102. The plate 202s of tube 202 isconnected through a resistor 205 to one side of the operating coil 206aof a motorreversing relay 206. The other side of coil 206a is com nectedthrough normally-open contacts 208a of a timedelay relay 208 to powersupply circuit 102. A capacitor 210 is connected across relay coil 206a.The biasing grid 202d of tube 202 is connected to power supply circuit102. A biasing or firing grid 202e of tube 202 is connected to asensitivity-control rheostat 210 through a conductor 212. Rheostat 210is connected through resistors 214 and 216 to conductor 200 whichsupplies the amplified register mark pulse. As hereinafter explained,presentation of a register mark pulse signal to control grid 202e oftube 202 can effect firing of the thyratron only in the event that thethyratron is not in ungrounded condition as hereinafter explained. Morespecifically, control grid 202e of tube 202 is periodically grounded bytiming switch circuit 182 and is, therefore, unable to effect firing oftube 202.

Thyratron tube 204 comprises a heater element 204a which is connectedacross secondary winding 188d of power transformer 188. The cathode20411 of tube 204 is connected to power supply circuit 102. The plate204: of tube 204 is connected through a resistor 218 to one side of theoperating coil 220a of a motorreversing relay 220. The other side ofcoil 220a is connected through normally open contacts 208a of atimedelay relay 208 to power supply circuit 102. A capacitor 222 isconnected across relay coil 220a. The biasing grid 204d of tube 204 isconnected to power supply circuit 102. A biasing or firing grid 204e oftube 204 is connected to a sensitivity-control rheostat 226 through aconductor 224. Rheostat 226 is connected through resistors 228 and 230to conductor 200 which supplies the amplified register mark pulse. Ashereinafter explained, presentation of a register mark pulse signal tocontrol grid 204e of tube 204 can effect firing of the thyratron only inthe event that the thyratron is not in ungrounded condition. Morespecifically, control grid 204e of tube 204 is periodically grounded bytiming switch circuit 182 and is, therefore, unable to effect firing oftube 204.

If thyratron tube 202 or 204 is tired, the tube is held in firingcondition for a predetermined time interval by time-delay circuit 96 sothat relay 206 or 220 respectively may be energized for a length of timenecessary to effect energization of correction motor 66. Timedelaycircuit 96 comprises a multi-vibrator type electron tube 232, atime-delay relay 208 which comprises normally open relay contacts 208aand a relay coil 208b, and a potentiometer 234 for adjusting the lengthof the time delay. Heater element 232a of tube 232 is connected acrosssecondary winding 188d of power transformer 188. Relay coil 208b oftime-delay relay 208 is connected between plate 232b of tube 232 andpower supply circuit 102. The cathode 2320 of tube 232 is also connectedto power supply circuit 102. The control grid 232d of tube 232 isconnected to potentiometer 234. A resistor 236 is connected across contacts 208a of time-delay relay 208. The other plate 232e of tube 232 isconnected to a pair of balancing potentiometers 240 and 242 which, inturn, are connected to the sensitivity controls 210 and 226,respectively.

Motor reversing relays 206 and 220 comprise relay coils 206a and 220a,hereinbefore described, and sets of forward and reverse relay contacts206b and 220b, respectively. These sets of relay contacts are located inmotor reversing circuit 98, shown in FIG. 10. The set of forward relaycontacts 206k comprise a pair of stationary upper contacts 206a and206d; a pair of stationary lower contacts 206e and 206]"; and a pair ofmovable contacts 206g and 206k operated by relay coil 206a. The set ofreverse relay contacts 220b comprise a pair of stationary upper contacts22% and 220d; a pair of stationary lower contacts 220e and 220f; and apair of movable contacts 220g and 220k operated by relay coil 220a. lnmotor-reversing circuit 98, the sets of relay contacts 206b and 220b andthe leads 250, 252, 254 and 256 of motor 66 are interconnected asfollows to effect forward and reverse rotation of the motor when therelays are operated.

FIG. 10 shows both motor-reversing relays 206 and 220 in contact openposition whereby motor 66 is deenergized. When coil 2060 of forwardrelay 206 is energized to rotate motor 66 in the forward direction (forexample, to speed up meter roller 26), movable con tacts 206g and 206hof relay 206 move from the position shown in FIG. 10 to a positionwherein they engage the lower stationary contacts 206e and 206]",

respectively. In this condition, motor lead 252 is connected directly toline 186. Motor lead 254 is connected to line 184 through contact 2200,220g, conductor 256, contact 206k, contact 206 conductor 266, andcontact 226a. Motor lead 250 and motor lead 256 are connected in serieswith each other through contact 21162, 266g, 220k and 220d. Motor 66 isthus connected and energized for rotation in the forward direction tospeed up meter roller 26 as long as relay contacts 20612 are closed.When relay contacts 266b open, the movable contacts return to theposition shown in FIG. 16 and motor 66 stops.

When coil 220a of reverse relay 220 is energized to rotate motor 66 inthe reverse direction (for example, to slow down meter roller 26),movable contacts 220g and 226k of relay 220 move from the position shownin FIG. 16 to a position wherein they engage lower stationary contacts22% and 220 respectively. In this condition, motor lead 252 is connectedto line 186. Motor lead 256 is connected to line 184 through contact266d, 266k, conductor 256, contact 220g, and contact 2262. Motorconductors 250 and 254 are connected in series with each other throughcontact 220f, contact 221th, contact 206g, and contact 206c. Motor 66 isthus connected and energized for rotation in the reverse direction toslow down meter roller 26 as long as relay contacts 22Gb are closed.When relay contacts 22612 are open, the movable contacts 220g and 220kreturn to the position shown in FIG. 10 and motor 66 stops.

The forward and reverse relay contacts 206k and 22% are usually operatedin response to energization of the relay coils 206a and 220a,respectively, which are controlled by the thyratron tubes 202 and 2114,respectively. However, it is to be understood that forward and reverserelay contacts 2116b and 2211b can be operated to effect operation ofmotor 66 as hereinbefore described by normally open inching switches 264and 266, respectively, directly from power source 100 or by additionalnormally open inching switches 268 and 2711, respectively, in selectorswitch circuit 182.

Selector switch circuit 182 comprises timing or selector switch 66 whichhas two magnetic pickups 126 and 126, hereinbefore described. Themagnetic pickups 126 and 126 are connected to magnetic pickup relays 272and 276, respectively. The normally open contacts 272a of relay 272 haveone side connected to ground and the other side connected through aconductor 276 to sensitivity control 210 through resistor 214. Thenormally open contacts 274a of relay 274 have one side connected toground and the other side connected through a conductor 278 tosensitivity control 226 through resistor 228.

SCANNING AREA Timing or selector switch 68 operates to define a timeinterval or scanning interval which, for purposes of discussion, may beconsidered as an imaginary scanning area 15, shown in FIG. 3, which isdivided into three zones, namely, a retard zone 17, an in-register zone19, and an advance zone 21. Scanning area needs to be adjustable inseveral ways. First, the width of in-register zone 19 should be slightlywider that the width of a particular register mark 14. Second, theentire width of scanner area 15 should be such that it will notsuperimpose itself on any portion of a printed design 12, when tittedbetween two adjacent designs, as

FIG. 3 shows. in practice, assuming a one-to-one ratio between rotationof timer switch 66 and rotation of feeder roll 32 and one cycle ofoperation of cutter 341, the width of advance zone 21 is usuallyequivalent to about 30 of angular distance on feed roll 32. Similarly,the width of retard zone 17 of scanner area is usually equal to about 30degrees of angular distance on feed roller 32. In such a relationship,the width of advance zone 21 is equal to one-twelfth the cut-off lengthof each design and the width of retard zone 17 equal to one-twelfth thecut-off length of one design. For example, if a design is to be cutevery 12 inches on web 111, advance zone 21 would equal 1 inch andretard zone 17 would also equal 1 inch. The width of advance zone 21 isdetermined by the time setting of relay 272 and the width of retard zone17 is determined by the time setting of relay 2741. Advance zone 21 isadjustable toward and away from retard zone 17 so as to permit a desiredwidth of in-register zone 19. This adjustment is accomplished byangularly moving magnetic pickups 126 and 126 so as to enlarge ordiminish angle alpha between them. Scanning area 15 can also be shiftedtoward or away from point 86 shown in FIG 3. Such shifting is accomplished by rotating magnetic pickups 126 and 126 simultaneously ineither the clockwise or counterclockwise direction with respect to FIG.5. As hereinafter explained in detail, scanning area 15 can be shiftedso that either advance zone 21, in-register zone 19, or retard zone 17appear to overlie point 86. If in-register zone 19 appears to overliepoint 86, the register mark pulse will be in register and no correctionof meter roll 26 will be initiated by motor 66. If scanning area 15 isshifted so that advance zone 21 appears to overlie point 86, theregister mark pulse comes up late and an advance signal is sent tocorrection motor 66 to speed up meter roll 26. If scanning area 15 isshifted so that retard zone 17 appears to overlie point 86, the registermark pulse comes too soon and a retard signal is sent to correctionmotor 66 to slow down meter roll 26 to bring the next register mark tocorrect position. Normally, scanning area 15 is adjusted so thatin-register zone 19 appears to overlie point 86. In this situation,correct cutting will occur. Misregistration caused by the register markpulse occurring too soon or too late with respect to in-register zone 19defined by timing switch 68 results in an appropriate correction signalbeing sent to correction motor 66.

Advance zone 21 is adjustable away from retard zone 17 so as to permit achange in the size of in-register zone 19, so that the width of thein-register zone is slightly larger than the width of a register mark.Changes in the width of in-register zone 19 are accomplished by movingthe magnetic pickups 126 and 126 on timing switch 68 with respect toeach other. For example, referring to FIGS. 5 and 111, if angle alpha isdecreased, the width of in-register zone 1'9 in scanning area 15 will beexpanded. Conversely, if angle alpha is increased, the width ofin-registerzone 1% will decrease. These adjustments are made as follows.Refer ring to P16. 4, both locks 152 and 151 are unlocked. The positionof magnetic pickup 126 is adjusted by turning dial 151) so that thebeginning of the scanning area can be adjusted at a predetermined pointin time with respect to cutter 34. Then, locking device 152 is locked sothat dial cannot be moved. Then, the. position of magnetic pickup 128with respect to magnetic pickup 126 is adjusted by turning dial 1411).Then locking device 154 is locked so that dial 142 cannot be moved. Theadjustments to switch 68 thus far described merely define the totalwidth of scanning area and, in particular, the width of in-register zone19.

It is apparent from the construction of switch 68 that the adjustmentsdescribed hereinbefore can be carried out while the web-cuttingapparatus and switch 68 are in operation.

In a situation where it is desired to shift the entire scanning area 15either forward or backward with respect to a register mark 14, assumingthat the size of the in-register area has been selected and switch 68adjusted accordingly, it is necessary to unlock locking de- -vice 154.Then cutter adjustment knob 174 is rotated in the desired direction andfor a desired amount so as to move both yokes 134 and 144 simultaneouslyfor the desired distance in the desired direction. This movement of bothyokes simultaneously has the effect of shifting the scanning area. Inpractice, it causes motor 66 to be energized sooner or later to effectadvance and retard corrections with respect to a point in the operationof cutting blade 134.

OPERATION The web cutting apparatus and control means in accordance withthe invention operate as follows. Assume that the web-cutting apparatusis in operation and that web 10 is passing under scanner head 80.Further assume that switch 190 is closed and that all control circuitsare receiving operating power. Also assume that selector switch 68 isrotating in the direction of arrow 11 and is in synchronism with thereciprocating operation of cutter blade 34 in a one-to-one ratio.Finally assume that notch 122 in the larger disc 116 of timing switch 68has just passed magnetic pickup 126 and that contacts 272a of pickuprelay 272 are closed. This closure of relay contacts 272a marks thestart of the scanning interval. The length of time contacts 272a remainclosed defines the width of retard zone 17 of scanning area 15. Withcontacts 272a closed, control grid 202e of thyratron tube 202 isgrounded through conductor 212, sensitivity control 210, conductor 276,and contacts 272a. However, since contact 274a of pickup relay 274 areopen, the control grid 2042 of thyratron tube 204 is ungrounded.

Now assume that a register mark 14 interrupts the light beam from lightsource 82 to photoelectric cells 88 and 90 as web 10 passes underscanner head 80. Further assume that this interruption occurs whilepickup relay 272 is closed, i.e., that the register mark pulse occurs inretard zone 17 of scanning area 15. Interruption of the light beamcauses photoelectric cells 88 and 90 to produce a register mark pulse inconductor 196 which is transmitted to amplifier tube 194 and amplifiedtherein. The amplified register pulse is transmitted through conductor200 and through both sensitivity controls 210 and 226 and throughconductors 212 and 224, respectively, to the control grids 202a and204e, respectively, of the thyratron control tubes 202 and 204,respectively. Since conrol grid 202a of tube 202 is grounded, thepresentation of the amplified register mark pulse to its control grid202e is ineffective to fire tube 202. However, since tube 204 isungrounded, appearance of the amplified register mark pulse at itscontrol grid 204:: causes tube 204 to fire. When tube 204 fires, relaycoil 220a of motor relay 220 is energized and contacts 220a of motorreversing relay 220 close to energize motor 66 for rotation in thereverse (retard) direction. Tube 204 is held on firing condition andrelay 220 remains energized for a time interval determined by the lengthof time timing relay contacts 208a of timing circuit 96 remain closed.When this in terval expires, timing relay contacts 208a open todeenergize relay coil 220a of motor relay 220. As discs 116 and 118 oftiming switch 68 continue to kotate,

contacts 272a of pickup relay 272 reopen and tube 202 is no longergrounded.

Now assume that interruption of the light beam occurs while pick-uprelays 272 and 274 are both open, i.e., in the in register zone ofscanning area. As is apparent, the amplified register mark pulse is thenpresented to control grids 202e, 204e of tubes 202 and 204simultaneously, but since relay contacts 208a of timing relay 208 areopen, neither coil 204a nor coil 220a of motor relays 206 and 220 willbe energized and no correction signal will be presented to motor 66. Inthis situation, the register mark pulse appears in the inregister zoneof scanning area.

As discs 116 and 118 of timing switch 68 continue to rotate, a point isreached where slot 124 of inner disc 118 passes magnetic pickup 128,thereby causing pickup relay 274 to be energized and its contacts 27411to close for a predetermined interval of time. The length of timecontacts 274a remain closed defines the width of advance zone 19 ofscanning area 15. With contacts 2740 closed, tube 204 is groundedbecause its control grid 204e is connected to ground through conductor224, sensitivity control 226, resistor 228, conductor 278 and contacts274a.

Now assume that the interruption of the light beam occurs while pickuprelay 274 is closed, i.e., in the advance zone of scanning interval.Since the amplified register mark pulse is presented to control grid204e of tube 204 while tube 204 is grounded, tube 204 will not fire.However, the register mark pulse is simultaneously presented to controlgrid 2022 of tube 202 while tube 202 is ungroundecl and tube 202 fires.Relay coil 206a of motor relay 206 is thereby energized, its contacts206e close and motor 66 is energized for rotation in the forward(advance) direction to increase the speed of meter roll 26. Tube 202 isheld in firing condition and relay 206 remains energized for a timeinterval determined by the length of time timing relay contacts 208a oftiming circuit 96 remain closed. When this time interval expires, timingrelay contacts 208a open to deenergize relay coil 206a of motor relay206.

I claim:

1. Web processing apparatus for a web containing repeated designs andcorresponding register marks comprising:

a processing device operable to perform a process on each design, feedmeans for repeatedly feeding a predetermined length of web to saidprocessing device, and

metering means for supplying a predetermined length of web to said feedmeans, said metering means normally operating at a constant speed whensaid designs are in registry with said processing device, and

control means for said web processing apparatus for maintaining thedesigns in registry with said processing device, said control meanscomprising:

correction means operable to momentarily change the speed of saidmetering means to supply a different length of web to said feed means,

scanning means in fixed location with respect to said processing devicefor sensing passage of a register mark and for providing a register markpulse in response thereto,

a selector switch responsive to the position of said processing devicefor providing output signals for each cycle of operation of saidprocessing device definitive of a scanning interval during which aprocess will be performed on a design by said processing device, saidscanning interval comprising advance, retard and in-register zones, and

a control circuit for comparing the relationship of a register markpulse to a scanning interval and for providing a correction signal tosaid correction means in the event said register mark pulse occurs at atime during said scanning interval other than in the in-register zone;said selector switch comprising:

a pair of pulse'producing means for producing a pair of output pulsesspaced apart in time which define the limits of said scanning intervalfor a cycle of operation of said processing device,

first adjustable means for selectively changing the length of thespacing between said pulse producing means to change the time intervalbetween said pair of pulses to change the width of said scanninginterval, and

second adjustable means for selectively changing the position of atleast one of said pulse producing means to shift one end of the timeinterval with respect to the cycle of operation of the processing deviceso as to shift the scanning interval with respect to the processingdevice.

2. The combination according to claim 1 wherein said pulse producingmeans comprises a support, a pair of pickup devices mounted on saidsupport, and rotatable means synchronized with the cycle of operation ofsaid processing device for causing said pickup devices to produce saidoutput pulses.

3. The combination according to claim 2 wherein said first adjustablemeans in said selector switch comprises means for changing the angulardistance between said pair of pickup devices.

4. The combination according to claim 3 wherein said second adjustablemeans in said selector switch comprises means for changing the: relativeangular relationship between said pair of pickup devices and saidrotatable means.

5. The combination according to claim 4 including a shaft rotatable onsaid support and on which said rotatable means are fixed, and whereinsaid first and second adjustable means comprise a pair of movable yokesmounted on said support, each yoke supporting one of said pickupdevices.

6. The combination according to claim 5 wherein said rotatable meanscomprise a pair of discs mounted on said shaft, each disc beingassociated with one pickup device and having means thereon for actuatingits associated pickup device.

7. The combination according to claim 6 wherein said pickup devices aremagnetic pickup devices and wherein the means on each disc for actuatingan associated pickup device is a discontinuity in the disc.

1. Web processing apparatus for a web containing repeated designs andcorresponding register marks comprising: a processing device operable toperform a process on each design, feed means for repeatedly feeding apredetermined length of web to said processing device, and meteringmeans for supplying a predetermined length of web to said feed means,said metering means normally operating at a constant speed when saiddesigns are in registry with said processing device, and control meansfor said web processing apparatus for maintaining the designs inregistry with said processing device, said control means comprising:correction means operable to momentarily change the speed of saidmetering means to supply a different length of web to said feed means,scanning means in fixed location with respect to said processing devicefor sensing passage of a register mark and for providing a register markpulse in response thereto, a selector switch responsive to thE positionof said processing device for providing output signals for each cycle ofoperation of said processing device definitive of a scanning intervalduring which a process will be performed on a design by said processingdevice, said scanning interval comprising advance, retard andin-register zones, and a control circuit for comparing the relationshipof a register mark pulse to a scanning interval and for providing acorrection signal to said correction means in the event said registermark pulse occurs at a time during said scanning interval other than inthe in-register zone; said selector switch comprising: a pair of pulseproducing means for producing a pair of output pulses spaced apart intime which define the limits of said scanning interval for a cycle ofoperation of said processing device, first adjustable means forselectively changing the length of the spacing between said pulseproducing means to change the time interval between said pair of pulsesto change the width of said scanning interval, and second adjustablemeans for selectively changing the position of at least one of saidpulse producing means to shift one end of the time interval with respectto the cycle of operation of the processing device so as to shift thescanning interval with respect to the processing device.
 2. Thecombination according to claim 1 wherein said pulse producing meanscomprises a support, a pair of pickup devices mounted on said support,and rotatable means synchronized with the cycle of operation of saidprocessing device for causing said pickup devices to produce said outputpulses.
 3. The combination according to claim 2 wherein said firstadjustable means in said selector switch comprises means for changingthe angular distance between said pair of pickup devices.
 4. Thecombination according to claim 3 wherein said second adjustable means insaid selector switch comprises means for changing the relative angularrelationship between said pair of pickup devices and said rotatablemeans.
 5. The combination according to claim 4 including a shaftrotatable on said support and on which said rotatable means are fixed,and wherein said first and second adjustable means comprise a pair ofmovable yokes mounted on said support, each yoke supporting one of saidpickup devices.
 6. The combination according to claim 5 wherein saidrotatable means comprise a pair of discs mounted on said shaft, eachdisc being associated with one pickup device and having means thereonfor actuating its associated pickup device.
 7. The combination accordingto claim 6 wherein said pickup devices are magnetic pickup devices andwherein the means on each disc for actuating an associated pickup deviceis a discontinuity in the disc.